Sustainable Conditional Tunnel Inspection: London Underground

Abstract

Since London underground opened as the world’s pioneer underground railway, the network has grown exponentially to over 402km, servicing more than 1.34 billion customers annually. The rail network is over 150 years and is deteriorating, therefore, it is imperative that innovative maintenance techniques are implemented to inspect the condition of the tunnels and to scope for repair works. Innovation can be difficult to implement due to the size of the London Underground. This study evaluates the practical application and performance of the innovative conditional laser tunnel inspection compared to the currently used traditional method. The results show the accuracy of the lasers, along with the software’s ability to create the scoring for a Principal Inspection report in accordance with the London Underground Standards. Though the initial cost is higher, this would be regained from the saving in maintenance works carried out during the four years between the Principal Inspections.